1. Field
Example embodiments relate to a method to determine an exposure start position and orientation of a substrate in maskless lithography and/or an apparatus to determine the exposure start position and orientation.
2. Description of the Related Art
Generally, a method to form a pattern on a substrate (or a semiconductor wafer) constituting a Liquid Crystal Display (LCD), Plasma Display Panel (PDP), or a Flat Panel Display (FPD) includes applying a pattern material to the substrate, selectively exposing the pattern material using a photo-mask, and selectively removing a part of the pattern material, chemical properties of which are changed, or the remaining part, so as to form a pattern.
However, as a substrate size increases and pattern feature widths become increasingly narrow, a maskless lithography method to form a desired pattern on a substrate (or a semiconductor wafer) without using a photo-mask has been developed. Maskless lithography has several advantages, for example, free design of a panel without mask fabrication/washing/storage costs, reduced lead time due to elimination of a mask fabrication process, no mask defects, no process loss, and increased production flexibility due to hybrid layout.
In such maskless lithography, accurately forming a pattern in a required exposure region of the substrate may require loading and orienting the substrate to coincide with an exposure scan direction (orientation) after assembly of equipment. Here, the equipment includes, for example, a loader to load or unload the substrate and a measurement system to measure an exposure start position and orientation of the substrate.
However, assembling equipment to coincide the loading and orientation of the substrate with the exposure scan direction is difficult. Therefore, it may be desirable to locate an exposure start position and orientation of the substrate.